rotate
``` ```
% rotate.pi (in Picat)
% Round 1A 2010
% Problem A. Rotate
%
% to use: picat rotate < input_file > output_file
%

import util.

main =>
foreach(TC in 1..T)
N = to_int(NToken),
K = to_int(KToken),
Table = {read_line().to_array() : _ in 1..N},
do_case(TC, N, K, Table)
end.

do_case(TC, N, K, Table) =>
Table1 = Table.rotate(N).drop(N),
(check(N, Table1, ['R' : _ in 1..K]) -> Red = 1; true),
(check(N, Table1, ['B' : _ in 1..K]) -> Blue = 1; true),
output(TC, Red, Blue).

rotate(Table, N) = RTable =>
RTable = new_array(N, N),
foreach (R in 1..N, C in 1..N)
RTable[C, N-R+1] = Table[R, C]
end.

drop(Table, N) = DTable =>
DTable = new_array(N, N),
foreach (C in 1..N)
Col = [Table[R, C] : R in 1..N],
RBs = delete_all(Col, '.'),
NDots = N-len(RBs),
NewCol = ['.' : _ in 1..NDots] ++ RBs,
[DTable[R, C] : R in 1..N] = NewCol
end.

check(N, Table, Str),
between(1, N, R),
Row = Table[R].to_list(),
append(_, Str, _, Row)
=>
true.
check(N, Table, Str),
between(1, N, C),
Col = [Table[R, C] : R in 1..N],
append(_, Str, _, Col)
=>
true.
check(N, Table, Str),
between(1, 2*N, D),
Diag = [Table[R, C] : R in 1..N, C = D-R, C >= 1, C <= N],
append(_, Str, _, Diag)
=>
true.
check(N, Table, Str),
between(1-N, N-1, D),
Diag = [Table[R, C] : R in 1..N, C = R-D, C >= 1, C <= N],
append(_, Str, _, Diag)
=>
true.

output(TC, 1, 1) =>
writef("Case #%w: Both\n", TC).
output(TC, 1, _) =>
writef("Case #%w: Red\n",  TC).
output(TC, _, 1) =>
writef("Case #%w: Blue\n", TC).
output(TC, _, _) =>
writef("Case #%w: Neither\n", TC).
``````